Mineralogical characteristics and spatial distribution of different age fractures in granites and pegmatites of the «Vozrozhdenie» deposit («Kawantsaari»), the Vyborg massif
- Ph.D., Dr.Sci. Head of Department National Mineral Resources University (Mining University)
Abstract
The unique size of monolithic blocks of granite in the «Vozrozhdenie» deposit («Kawantsaari») is due to the stability of these rocks in the steeply dipping and probably crosscutting part of the massif, where the rocks have retained their massive texture and have been least modified at the stage of formation of rare-metal pegmatites. The shape and size of monolithic blocks are determined by the pattern of disturbances, in the formation of which the leading role belongs to three steeply dipping zones of tectonic fractures of the North-West strike with the haloes of changes in the conditions of low-temperature acidic metasomatism. Later tectonic disruptions in these zones led to the destruction of rock blocks between them within a series of transverse fractures and to subhorizontal discontinuities of rocks caused probably by gravitational unloading of the massif and glacier action. The distribution of fractures in all directions is characterized by equal spacing («step»).
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